JP3369423B2 - Heat roll - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat roll for a printer such as an ink jet printer, and more particularly to a heat roll capable of high speed drying of ink on paper or an OHP sheet.

[0002]

2. Description of the Related Art In printers such as ink jet printers, water-based inks containing water as a solvent are usually used in terms of safety. Since the solvent of water-based ink is water, the drying speed of the ink after printing is slow, and this drying time is a factor that slows the printing speed of the ink jet printer.

On the other hand, in other print recording apparatuses, it has been proposed to heat a paper or an OHP (overhead projector) sheet using a heat roll before and after printing in order to dry the water-based ink after printing at high speed. As this heat roll, a heat roll in which a silicone rubber elastic layer is formed on a metal core has been proposed from the viewpoints of slip resistance and heat resistance when a paper or OHP sheet is conveyed.

However, in this method, when the OHP sheet is used, there is a problem that the sheet is wound around the roll surface due to the adhesiveness of the surface peculiar to the silicone rubber, which hinders the transportation.

In order to solve this problem, as a method of subjecting the roll to non-adhesive treatment, the inner surface of the roll molding die is
After coating organohydrogenpolysiloxane having at least 3 silicon-bonded hydrogen atoms in one molecule, and then placing the metal core of the roll inside this mold, by curing inside the mold, A method (Japanese Patent Publication No. 6-88281, Japanese Patent Publication No. 7-99170) in which a liquid silicone rubber capable of forming a cured product having a hardness of 30 or less is injected and cured by heating is known.

However, in such a method using a mold, it is difficult to obtain a thin molded body having a silicone rubber layer having a thickness of, for example, about 50 to 200 μm, and the rubber layer becomes thicker to obtain a heat roll. It is also disadvantageous.
Further, in this method, the organohydrogenpolysiloxane is not evenly penetrated into the rubber layer and the cured layer of the organohydrogenpolysiloxane is formed on the surface layer, so the surface layer becomes very brittle and wear resistant. Property deteriorates and durability becomes a problem. Furthermore, according to this method, when the proportion of hydrogen atoms in the organic groups such as methyl groups and ethyl groups and the substituents such as hydrogen atoms that are bonded to the silicon atoms of the organohydrogenpolysiloxane is small, the rubber layer becomes non-adhesive. On the other hand, when the proportion of the hydrogen atoms is large and the degree of polymerization is high, the surface layer portion of the rubber layer becomes hard and brittle, and the rubber layer may be formed depending on the molecular constitution and the degree of polymerization of the organohydrogenpolysiloxane. There is a drawback that it does not exhibit non-adhesiveness or that the surface layer portion is hardened or weakened.

As another method for making the surface of the silicone rubber non-tacky, there is a method of adding a filler such as fluororesin, boron nitride or graphite to the silicone rubber composition. Since detackification by addition requires a considerable amount of filler, the strength of the rubber layer decreases, and as a result, similar to the method using a mold,
Abrasion resistance is significantly deteriorated, causing a problem in durability.

[0008]

The object of the present invention is to rapidly dry the ink on the paper or OHP sheet by detackifying the roll surface by a simple method without impairing the abrasion resistance. It is also intended to provide a heat roll having excellent transportability, in which the OHP sheet is not wrapped around the roll surface.

In order to achieve the above object, the present invention provides a heat roll having a silicone rubber elastic layer on a metal core, wherein the silicone rubber elastic layer is made of silicone rubber having the following general formula (1):

[0010]

[Chemical 2] (In the formula, R ¹ is a group selected from an unsubstituted or substituted -valent hydrocarbon group and a hydrogen atom which do not independently contain an aliphatic unsaturated bond, and R ² independently does not contain an aliphatic unsaturated bond. It is an unsubstituted or substituted monovalent hydrocarbon group, and a and b are
an integer satisfying a ≧ 1 (however, when a = 1, at least one of R ¹ is a hydrogen atom), b ≧ 0, a + b ≦ 50, and 0.3 ≦ a / (a + b) ≦ 1.0 . ] The heat roll characterized by permeating and hardening the organohydrogen polysiloxane represented by these.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The heat roll of the present invention is a heat roll having a silicone rubber elastic layer on a metal core, in which the organohydrogenpolysiloxane of the general formula (1) is permeated and cured in the silicone rubber. Metal Core The metal core (also referred to as a cored bar) used in the heat roll of the present invention may be one used in a known heat roll, and examples thereof include metal cores such as aluminum, steel, and stainless steel.

Silicone Rubber Elastic Layer In the heat roll of the present invention, the silicone rubber elastic layer itself is typically a silicone rubber composition containing (A) organopolysiloxane, (B) filler and (C) curing agent. Is molded into a suitable thickness by molding, coating, etc.,
It is formed by curing. Used here
Representative examples of the components (A) to (C) are as follows.

Organopolysiloxane of component (A): This organopolysiloxane has, for example, the general formula (2):

[Chemical 3] [R in the formula³Are independently unsubstituted and contain no aliphatic unsaturated bonds
Or a substituted monovalent hydrocarbon group, R^FourIs an alkenyl group
X is a hydrogen atom or the general formula (3): -Si (R^Five)_p(R⁶)_3-p (3) (However, R^FiveIs an unsubstituted or substituted -valent hydrocarbon group,
R⁶Is an alkenyl group, and p is an integer of 1 to 3. )
Is a triorganosilyl group represented by and c and d are 0 or less.
Is an integer above, and c + d has a viscosity at 25 ° C of 100 to
It is an integer that is 10,000,000 cSt. ]
is there.

In the general formula (2), the unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond for R ³ is, for example, an alkyl group such as a methyl group, an ethyl group, a propyl amount or an isopropyl group. Groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl amount; aryl groups such as phenyl group, tolyl group, xylyl group; aralkyl groups such as benzyl group, phenylethyl group; and hydrogen atoms bonded to carbon atoms of these groups. Group or all of which is substituted with a halogen atom such as fluorine, chlorine or bromine, or a substituent such as cyano group, for example, chloromethyl group, 3,3,3-trifluoropropyl group, fluorophenyl group, etc. . Typical R ³
Has 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, among which a methyl group, a phenyl group and a 3,3,3-trifluoropropyl group are preferable, and a methyl group is particularly preferable.

In the general formula (2), examples of the alkenyl group represented by R ⁴ include vinyl group, allyl group, propenyl group,
Examples thereof include an isopropenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group. Among them, a lower alkenyl group having 2 to 3 carbon atoms such as a vinyl group and an allyl group is preferable, and a vinyl group is particularly preferable.

In the general formula (3), specific examples of the unsubstituted or substituted monovalent hydrocarbon group for R ⁵ include the unsubstituted or substituted monovalent hydrocarbon groups exemplified as R ^3. Specific examples of the alkenyl group of ⁶ include the alkenyl groups exemplified as R ⁴ .

Filler of component (B): The filler is a component blended for the purpose of improving the mechanical strength, heat conductivity, conductivity, etc. of the silicone rubber, and is usually used for general silicone rubber. Any of the above can be used. Examples of such fillers include reinforcing fillers such as fumed silica, precipitable silica, carbon powder, titanium dioxide, and quartz powder; thermal conductivity of aluminum oxide, boron nitride, aluminum nitride, magnesium oxide, and the like. Filler; conductive fillers such as powder powder, nickel, silver, silver-coated glass, etc. may be mentioned.

These fillers are preferably blended in the range of 10 to 300 parts, particularly 20 to 200 parts, relative to 100 parts (A) of the component (A) (parts by weight, the same hereinafter). If the content of the filler is less than 10 parts, a sufficient reinforcing effect cannot be obtained, and if the content exceeds 300 parts, the mechanical strength of the cured product decreases. May occur.

Curing agent of component (C): As a curing agent, for example
For example, the organic peroxide and the hydrogen atom bonded to the silicon atom
Organohydrogen having at least two in the molecule
Examples include polysiloxane. As the organic peroxide,
Commonly used in organic peroxide-curable silicone rubber compositions.
Any of the above can be used.
-Oxide, 2,4-dichlorobenzoyl peroxide
De, 4-chlorobenzoyl peroxide, dicumylper
Oxide, tert-butyl peroxide, 2,5-dimethyl
-2,5-bis (tert-butylperoxy) hexane
To be These may be used alone or in combination of two or more.
Can be used. Compounding amount of these organic peroxides
Is usually 0.2 to 5 parts per 100 parts of component (A) is preferred.
Yes.

When the above-mentioned organohydrogenpolysiloxane is used as the curing agent, the organopolysiloxane as the component (A) has two or more aliphatic unsaturated groups (alkenyl groups) in one molecule. To be done. That is, in the case of a silicone rubber composition containing such an organohydrogenpolysiloxane as a curing agent, (A)
An aliphatic unsaturated group in the component organopolysiloxane,
The composition is cured by an addition reaction (hydrosilylation reaction) that occurs with hydrogen atoms bonded to silicon atoms in the organohydrogenpolysiloxane (C). As the organohydrogenpolysiloxane, any of those commonly used in addition reaction-curable silicone rubber compositions can be used, but in the present invention, those represented by the following general formula (4) are particularly preferable. General formula (4):

[0022]

[Chemical 4] (In the formula, R ⁷ is an unsubstituted or substituted monovalent hydrocarbon group having no hydrogen atom or an aliphatic unsaturated group, R ⁸ and R ⁹ may be the same or different, and have no aliphatic unsaturated group. It is an unsubstituted or substituted monovalent hydrocarbon group, e is an integer of 1 or more (however, in the case of e = 1, at least one of R ⁷ is a hydrogen atom), and f is an integer of 0 or more. ]

In the general formula (4), among R ⁷ , an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated group is, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group; Examples of such groups include a 3,3,3-trifluoropropyl group in which part or all of hydrogen atoms bonded to carbon atoms of these alkyl groups are substituted with fluorine atoms. Especially preferred as R ⁷ is a hydrogen atom or a methyl group.

In the general formula (4), R ⁸ and R ⁹ are unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated group, and examples thereof include those exemplified as R ⁷ . A methyl group is particularly preferable as R ⁸ and R ⁹ .

The organohydrogen polysiloxane preferably has a viscosity at 25 ° C. of 1000 cPs or less. Further, this organohydrogenpolysiloxane, the number of hydrogen atoms bonded to the silicon atom per alkenyl group in the alkenyl group-containing organopolysiloxane of the component (A) is preferably at least 1, more preferably 1 It is preferable to mix them in an amount such that the number is up to 5.

In the present invention, when an organohydrogenpolysiloxane is used as a curing agent, a well-known platinum group metal catalyst as an addition reaction catalyst, that is, a platinum-based catalyst, a palladium-based catalyst and a rhodium-based catalyst is used in combination. Platinum-based catalysts are preferably used. Examples of platinum-based catalysts include platinum black, chloroplatinic acid, and complexes of chloroplatinic acid with olefins such as ethylene; alcohols; aldehydes; vinylsilanes; or vinylsiloxanes. The addition amount of these addition reaction catalysts is usually 1 to 500 ppm, preferably 5 to 20 ppm in terms of platinum group metal based on 100 parts by weight of the component (A).

In the silicone rubber composition used in the present invention, in addition to the above-mentioned components (A), (B) and (C), various compounding agents well known in the art may be added, if necessary. You can Examples of the compounding agent include diphenylsilanediol, dispersants such as hexamethyldisilazane, which has a low degree of polymerization and has a molecular chain end hydroxyl group-blocked dimethylpolysiloxane having a viscosity of less than 100 cP at 25 ° C .; ferrous oxide, and secondary oxide Examples thereof include heat resistance improvers such as iron, cerium oxide, and iron octylate; coloring agents such as pigments and dyes; and reinforcing agents such as vinyl group-containing silicone resins.

To form a silicone rubber elastic layer on a metal core using the above silicone rubber composition, a conventional method may be used. For example, the surface of the metal core may be washed and degreased to improve adhesion. Therefore, first, apply a primer and air dry. If necessary, bake by heating at 100 to 180 ° C for about 5 to 30 minutes. Then, the above-mentioned silicone rubber composition is applied thereon by a molding method such as press molding or injection molding, or by spray coating, dip coating, knife coating or the like, depending on the thickness of the elastic layer to be obtained. And then cured to form a silicone rubber elastic layer. Generally, in consideration of thermal efficiency, it is preferable that the elastic layer is as thin as possible, and in consideration of the balance with abrasion resistance, it is preferably 10 to 500 μm, particularly preferably 20 to 200 μm. When the rubber layer is thinly formed, a coating method is preferable. Suitable curing conditions for forming the elastic layer are 50 to 200 ^° C. and 0.5 minutes to 2 hours.

As another method for forming the silicone rubber elastic layer on the metal core, only the silicone rubber elastic layer is previously molded by the above-mentioned molding method, and then the above-mentioned general formula is applied.
A method may be mentioned in which the organohydrogenpolysiloxane represented by (1) is permeated and cured, and then the elastic layer is bonded to the metal core.

The heat roller organohydrogenpolysiloxane invention penetrate the organohydrogenpolysiloxane silicone rubber elastic layer is represented by the general formula to the silicone rubber (1), those obtained by curing. Therefore, when manufacturing the heat roll of the present invention, after the silicone rubber elastic layer is provided on the metal core,
The organohydrogenpolysiloxane represented by (1) may be infiltrated and cured, or a silicone rubber elastic layer may be formed in advance and the organohydrogenpolysiloxane may be infiltrated and cured, and then the elasticity may be applied. The layer may be adhered to the metal core.

The organohydrogenpolysiloxane represented by the general formula (1) used here is a component for modifying the silicone rubber elastic layer, and eliminates tackiness on the surface of the silicone rubber elastic layer. , Greatly contributes to the prevention of sticking of the OHP sheet.

In the general formula (1), the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated group represented by R ¹ is exemplified as R ³ in the general formula (2). Those exemplified, preferably a hydrogen atom or a carbon atom number 1
To 5 alkyl groups, more preferably a hydrogen atom or a methyl group.

Specific examples of the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated group for R ² in the general formula (1) include those exemplified as R ³ in the general formula (2). Of these, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group is more preferable.

Further, in order for the organohydrogenpolysiloxane as the treating agent to exert the desired effect of preventing tackiness, a in the general formula (1) is an integer of 1 or more, preferably an integer of 3 or more, b is an integer of 0 or more.

Further, in order to uniformly permeate the organohydrogenpolysiloxane into the silicone rubber elastic layer, it is necessary that the degree of polymerization (a + b) is 50 or less, and preferably the degree of polymerization is 15 It is the following. If the degree of polymerization is larger than this, the silicone rubber elastic layer does not uniformly permeate, and a cured layer of organohydrogenpolysiloxane is formed on the surface layer, so that the surface layer becomes extremely hard and brittle and wear resistance is reduced. Extremely low.

On the other hand, in order for the organohydrogenpolysiloxane as the treating agent to sufficiently exert the desired effect of preventing tackiness, it is necessary to make the surface coating appropriately hard, and for that purpose, in the general formula (1), It is necessary that a / (a + b) is 0.3 or more and 1.0 or less.

To produce the heat roll of the present invention, the organohydrogenpolysiloxane (liquid) is used as it is or, if necessary, diluted with a solvent such as toluene, xylene, heptane or hexane to prepare a solution, which is used as a gauze. , Apply it to the surface of the silicone rubber elastic layer with a brush or the like, or apply it to the surface by a coating method such as spray coating or dip coating to make it penetrate into the silicone rubber elastic layer, thereby promoting the above reaction and The impregnated portion of the layer may be cured. In this case, in order to obtain the desired cured film in a short time, 80 ~ 200 ℃, 3
It is preferable to perform the heat treatment under the condition of 0 seconds to 90 minutes.

[0038]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, parts represent parts by weight. Example 1 A core made of aluminum as a core of a heat roll (outer diameter 70 m
A silicone-based primer (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: Primer No. 101A / B) was applied onto mφ, length 280 mm) and baked at 150 ° C. for 15 minutes. Then, a solution of addition-curable silicone rubber composition (Shin-Etsu Chemical Co., Ltd., trade name: X-34-279A / B) diluted with toluene was applied by spray coating, and then heated at 180 ° C for 1 hour. Then, a 100 μm-thick silicone rubber elastic layer was formed on the aluminum cored bar. Next, on the surface of this silicone rubber elastic layer, the following formula (5):

[0039]

[Chemical 5] 40 of the organohydrogenpolysiloxane represented by
A wt% heptane solution was applied with gauze and heat-treated at 180 ° C. for 1 hour to manufacture a target heat roll.

When this heat roll was attached to an ink jet printer and printed on paper and OHP sheet,
The sheet was not wrapped around, and the paper and OHP sheet were not slipped, and good heating and conveyance as a heat roll was possible.

Example 2 Instead of the 40 wt% heptane solution of the organohydrogenpolysiloxane used for the treatment of the silicone rubber elastic layer, the following formula (6):

[Chemical 6] A heat roll was manufactured by the same method as in Example 1 except that the organohydrogenpolysiloxane represented by

When the obtained heat roll was mounted on an ink jet printer and printed on paper and OHP sheet, there was no winding of the OHP sheet and slippage of the paper and OHP sheet, and good heating and transport as a heat roll. It was possible.

Example 3 Instead of the 40 wt% heptane solution of the organohydrogenpolysiloxane used for the treatment of the silicone rubber elastic layer, the following formula (7):

[Chemical 7] 75 of organohydrogenpolysiloxane represented by
A heat roll was manufactured in the same manner as in Example 1, except that a wt% heptane solution was used.

When the obtained heat roll was mounted on an ink jet printer and printed on paper and OHP sheet, there was no winding of the OHP sheet and no slippage of the paper and OHP sheet, and good heating and conveyance as a heat roll It was possible.

Example 4 A core made of aluminum as a core of a heat roll (outer diameter 70 m
A silicone-based primer (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-93-802) was applied onto mφ, length 280 mm). On top of that, 100 parts of organic peroxide-curable silicone rubber compound (trade name: KE7010U, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.6 part of bis-2,4-dichlorobensoyl peroxide as an organic peroxide-based curing agent. After diluting the mixture prepared by diluting the mixture in
After heat treatment for 2 minutes and subsequently at 200 ° C. for 2 hours, a silicone rubber elastic layer having a thickness of 150 μm was formed on the aluminum cored bar.

Next, on the surface of this silicone rubber elastic layer,
The organohydrogenpolysiloxane of the formula (6) used for the surface treatment in Example 2 was directly coated with gauze,
Heat treatment was performed at a temperature of 1 ° C. for 1 hour to produce a desired heat roll. When the obtained heat roll was mounted on an inkjet printer and printed on paper and an OHP sheet, there was no winding of the OHP sheet and no slippage of the paper and OHP sheet, and good heating and conveyance as a heat roll was possible. It was

Comparative Example 1 In the same manner as in Example 1, a 100 μm thick silicone rubber elastic layer was formed on an aluminum cored bar to manufacture a comparative heat roll. When the obtained heat roll for comparison was mounted on an ink jet printer and printed on paper and OHP sheet, there was no slippage of paper and OHP sheet, and there was no problem in paper transportability, but the adhesiveness of the roll surface By OH
Wrapping of the P sheet was severe, and there was a problem in the transportability of the OHP sheet.

Comparative Example 2 Instead of the 40 wt% heptane solution of the organohydrogenpolysiloxane used for the surface treatment of the silicone rubber elastic layer, the following formula (8):

[Chemical 8] A heat roll for comparison was produced in the same manner as in Example 1 except that the organohydrogenpolysiloxane represented by the above was used as it was.

When the obtained heat roll for comparison was mounted on an ink jet printer and printed on a paper and an OHP sheet, there was no slippage of the paper and the OHP sheet, and there was no problem in the transportability of the paper, but the roll surface OH due to the stickiness of
Wrapping of the P sheet was severe, and there was a problem in the transportability of the OHP sheet.

[0050]

EFFECT OF THE INVENTION The heat roll of the present invention has the surface of the silicone rubber elastic layer made non-tacky without lowering the abrasion resistance, so that the OHP sheet is not wrapped around the roll surface, and the transportability and durability are improved. In addition to excellent properties, the ink on the paper or the OHP sheet can be dried quickly to greatly improve the printing speed.

─────────────────────────────────────────────────── ─── Continued Front Page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/01 G03G 15/20 103

Claims (2)

(57) [Claims] 1. In a heat roll having a silicone rubber elastic layer on a metal core, the silicone rubber elastic layer is made of silicone rubber having the following general formula (1): (In the formula, R ¹ is a group selected from an unsubstituted or substituted -valent hydrocarbon group and a hydrogen atom which do not independently contain an aliphatic unsaturated bond, and R ² independently does not contain an aliphatic unsaturated bond. It is an unsubstituted or substituted monovalent hydrocarbon group, and a and b are
an integer satisfying a ≧ 1 (however, when a = 1, at least one of R ¹ is a hydrogen atom), b ≧ 0, a + b ≦ 50, and 0.3 ≦ a / (a + b) ≦ 1.0 . ] A heat roll obtained by permeating and curing an organohydrogenpolysiloxane represented by: 2. The heat roll according to claim 1, wherein a + b in the general formula (1) is a + b ≦ 15.